What does the size number part affect and what does the s/r/l part affect? from what I understand, the chest size impacts the length of the shoulders, sleeves, suit, waist etc.(so two shorts of different size numbers will still have different lengths) but what does short/reg/long impact? will it impact the waist?
my suit sleeves are short, suit waist is tight and pants (came as a set) are way too tight. If I get the next size up, 38S (it's a 36S right now and they...

the sleeves are short, suit waist is tight and pants (came as a set) are too tight. If I get the next size up, 38S (it's a 36S right now and they don't make 36R) can I alter the shoulder width/suit length if too long?
from what I understand, the chest size impacts the length of the shoulders, sleeves, suit, waist etc.but what does short/reg/long impact? will it impact the waist?
Should I alter a smaller suit or larger suit?